brush.cc

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/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <array>
#include <optional>
 
#include "MEM_guardedalloc.h"
 
#include "DNA_ID.h"
#include "DNA_brush_types.h"
#include "DNA_defaults.h"
#include "DNA_material_types.h"
#include "DNA_scene_types.h"
 
#include "BLI_listbase.h"
#include "BLI_math_base.hh"
#include "BLI_math_rotation.h"
#include "BLI_rand.h"
 
#include "BLT_translation.hh"
 
#include "BKE_asset.hh"
#include "BKE_bpath.hh"
#include "BKE_brush.hh"
#include "BKE_colortools.hh"
#include "BKE_gpencil_legacy.h"
#include "BKE_grease_pencil.hh"
#include "BKE_idprop.hh"
#include "BKE_idtype.hh"
#include "BKE_lib_id.hh"
#include "BKE_lib_query.hh"
#include "BKE_lib_remap.hh"
#include "BKE_main.hh"
#include "BKE_material.h"
#include "BKE_paint.hh"
#include "BKE_preview_image.hh"
#include "BKE_texture.h"
 
#include "IMB_colormanagement.hh"
#include "IMB_imbuf.hh"
#include "IMB_imbuf_types.hh"
 
#include "RE_texture.h" /* RE_texture_evaluate */
 
#include "BLO_read_write.hh"
 
static void brush_init_data(ID *id)
{
  Brush *brush = (Brush *)id;
  BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(brush, id));
 
  MEMCPY_STRUCT_AFTER(brush, DNA_struct_default_get(Brush), id);
 
  /* enable fake user by default */
  id_fake_user_set(&brush->id);
 
  /* the default alpha falloff curve */
  BKE_brush_curve_preset(brush, CURVE_PRESET_SMOOTH);
}
 
static void brush_copy_data(Main * /*bmain*/,
                            std::optional<Library *> /*owner_library*/,
                            ID *id_dst,
                            const ID *id_src,
                            const int flag)
{
  Brush *brush_dst = (Brush *)id_dst;
  const Brush *brush_src = (const Brush *)id_src;
  if (brush_src->icon_imbuf) {
    brush_dst->icon_imbuf = IMB_dupImBuf(brush_src->icon_imbuf);
  }
 
  if ((flag & LIB_ID_COPY_NO_PREVIEW) == 0) {
    BKE_previewimg_id_copy(&brush_dst->id, &brush_src->id);
  }
  else {
    brush_dst->preview = nullptr;
  }
 
  brush_dst->curve = BKE_curvemapping_copy(brush_src->curve);
  brush_dst->automasking_cavity_curve = BKE_curvemapping_copy(brush_src->automasking_cavity_curve);
 
  if (brush_src->gpencil_settings != nullptr) {
    brush_dst->gpencil_settings = MEM_cnew<BrushGpencilSettings>(__func__,
                                                                 *(brush_src->gpencil_settings));
    brush_dst->gpencil_settings->curve_sensitivity = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_sensitivity);
    brush_dst->gpencil_settings->curve_strength = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_strength);
    brush_dst->gpencil_settings->curve_jitter = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_jitter);
 
    brush_dst->gpencil_settings->curve_rand_pressure = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_rand_pressure);
    brush_dst->gpencil_settings->curve_rand_strength = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_rand_strength);
    brush_dst->gpencil_settings->curve_rand_uv = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_rand_uv);
    brush_dst->gpencil_settings->curve_rand_hue = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_rand_hue);
    brush_dst->gpencil_settings->curve_rand_saturation = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_rand_saturation);
    brush_dst->gpencil_settings->curve_rand_value = BKE_curvemapping_copy(
        brush_src->gpencil_settings->curve_rand_value);
  }
  if (brush_src->curves_sculpt_settings != nullptr) {
    brush_dst->curves_sculpt_settings = MEM_cnew<BrushCurvesSculptSettings>(
        __func__, *(brush_src->curves_sculpt_settings));
    brush_dst->curves_sculpt_settings->curve_parameter_falloff = BKE_curvemapping_copy(
        brush_src->curves_sculpt_settings->curve_parameter_falloff);
  }
 
  /* enable fake user by default */
  id_fake_user_set(&brush_dst->id);
}
 
static void brush_free_data(ID *id)
{
  Brush *brush = (Brush *)id;
  if (brush->icon_imbuf) {
    IMB_freeImBuf(brush->icon_imbuf);
  }
  BKE_curvemapping_free(brush->curve);
  BKE_curvemapping_free(brush->automasking_cavity_curve);
 
  if (brush->gpencil_settings != nullptr) {
    BKE_curvemapping_free(brush->gpencil_settings->curve_sensitivity);
    BKE_curvemapping_free(brush->gpencil_settings->curve_strength);
    BKE_curvemapping_free(brush->gpencil_settings->curve_jitter);
 
    BKE_curvemapping_free(brush->gpencil_settings->curve_rand_pressure);
    BKE_curvemapping_free(brush->gpencil_settings->curve_rand_strength);
    BKE_curvemapping_free(brush->gpencil_settings->curve_rand_uv);
    BKE_curvemapping_free(brush->gpencil_settings->curve_rand_hue);
    BKE_curvemapping_free(brush->gpencil_settings->curve_rand_saturation);
    BKE_curvemapping_free(brush->gpencil_settings->curve_rand_value);
 
    MEM_SAFE_FREE(brush->gpencil_settings);
  }
  if (brush->curves_sculpt_settings != nullptr) {
    BKE_curvemapping_free(brush->curves_sculpt_settings->curve_parameter_falloff);
    MEM_freeN(brush->curves_sculpt_settings);
  }
 
  MEM_SAFE_FREE(brush->gradient);
 
  BKE_previewimg_free(&(brush->preview));
}
 
static void brush_make_local(Main *bmain, ID *id, const int flags)
{
  if (!ID_IS_LINKED(id)) {
    return;
  }
 
  Brush *brush = (Brush *)id;
  const bool lib_local = (flags & LIB_ID_MAKELOCAL_FULL_LIBRARY) != 0;
 
  bool force_local, force_copy;
  BKE_lib_id_make_local_generic_action_define(bmain, id, flags, &force_local, &force_copy);
 
  if (brush->clone.image) {
    /* Special case: `ima` always local immediately.
     * Clone image should only have one user anyway. */
    /* FIXME: Recursive calls affecting other non-embedded IDs are really bad and should be avoided
     * in IDType callbacks. Higher-level ID management code usually does not expect such things and
     * does not deal properly with it. */
    /* NOTE: assert below ensures that the comment above is valid, and that exception is
     * acceptable for the time being. */
    BKE_lib_id_make_local(bmain, &brush->clone.image->id, LIB_ID_MAKELOCAL_ASSET_DATA_CLEAR);
    BLI_assert(!ID_IS_LINKED(brush->clone.image) && brush->clone.image->id.newid == nullptr);
  }
 
  if (force_local) {
    BKE_lib_id_clear_library_data(bmain, &brush->id, flags);
    BKE_lib_id_expand_local(bmain, &brush->id, flags);
 
    /* enable fake user by default */
    id_fake_user_set(&brush->id);
  }
  else if (force_copy) {
    Brush *brush_new = (Brush *)BKE_id_copy(bmain, &brush->id); /* Ensures FAKE_USER is set */
 
    brush_new->id.us = 0;
 
    /* setting newid is mandatory for complex make_lib_local logic... */
    ID_NEW_SET(brush, brush_new);
 
    if (!lib_local) {
      BKE_libblock_remap(bmain, brush, brush_new, ID_REMAP_SKIP_INDIRECT_USAGE);
    }
  }
}
 
static void brush_foreach_id(ID *id, LibraryForeachIDData *data)
{
  Brush *brush = (Brush *)id;
 
  BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, brush->toggle_brush, IDWALK_CB_NOP);
  BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, brush->clone.image, IDWALK_CB_NOP);
  BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, brush->paint_curve, IDWALK_CB_USER);
  if (brush->gpencil_settings) {
    BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, brush->gpencil_settings->material, IDWALK_CB_USER);
    BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, brush->gpencil_settings->material_alt, IDWALK_CB_USER);
  }
  BKE_LIB_FOREACHID_PROCESS_FUNCTION_CALL(data, BKE_texture_mtex_foreach_id(data, &brush->mtex));
  BKE_LIB_FOREACHID_PROCESS_FUNCTION_CALL(data,
                                          BKE_texture_mtex_foreach_id(data, &brush->mask_mtex));
}
 
static void brush_foreach_path(ID *id, BPathForeachPathData *bpath_data)
{
  Brush *brush = (Brush *)id;
  if (brush->icon_filepath[0] != '\0') {
    BKE_bpath_foreach_path_fixed_process(
        bpath_data, brush->icon_filepath, sizeof(brush->icon_filepath));
  }
}
 
static void brush_blend_write(BlendWriter *writer, ID *id, const void *id_address)
{
  Brush *brush = (Brush *)id;
 
  BLO_write_id_struct(writer, Brush, id_address, &brush->id);
  BKE_id_blend_write(writer, &brush->id);
 
  if (brush->curve) {
    BKE_curvemapping_blend_write(writer, brush->curve);
  }
 
  if (brush->automasking_cavity_curve) {
    BKE_curvemapping_blend_write(writer, brush->automasking_cavity_curve);
  }
 
  if (brush->gpencil_settings) {
    BLO_write_struct(writer, BrushGpencilSettings, brush->gpencil_settings);
 
    if (brush->gpencil_settings->curve_sensitivity) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_sensitivity);
    }
    if (brush->gpencil_settings->curve_strength) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_strength);
    }
    if (brush->gpencil_settings->curve_jitter) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_jitter);
    }
    if (brush->gpencil_settings->curve_rand_pressure) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_rand_pressure);
    }
    if (brush->gpencil_settings->curve_rand_strength) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_rand_strength);
    }
    if (brush->gpencil_settings->curve_rand_uv) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_rand_uv);
    }
    if (brush->gpencil_settings->curve_rand_hue) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_rand_hue);
    }
    if (brush->gpencil_settings->curve_rand_saturation) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_rand_saturation);
    }
    if (brush->gpencil_settings->curve_rand_value) {
      BKE_curvemapping_blend_write(writer, brush->gpencil_settings->curve_rand_value);
    }
  }
  if (brush->curves_sculpt_settings) {
    BLO_write_struct(writer, BrushCurvesSculptSettings, brush->curves_sculpt_settings);
    BKE_curvemapping_blend_write(writer, brush->curves_sculpt_settings->curve_parameter_falloff);
  }
  if (brush->gradient) {
    BLO_write_struct(writer, ColorBand, brush->gradient);
  }
 
  BKE_previewimg_blend_write(writer, brush->preview);
}
 
static void brush_blend_read_data(BlendDataReader *reader, ID *id)
{
  Brush *brush = (Brush *)id;
 
  /* Falloff curve. */
  BLO_read_struct(reader, CurveMapping, &brush->curve);
 
  BLO_read_struct(reader, ColorBand, &brush->gradient);
 
  if (brush->curve) {
    BKE_curvemapping_blend_read(reader, brush->curve);
  }
  else {
    BKE_brush_curve_preset(brush, CURVE_PRESET_SHARP);
  }
 
  BLO_read_struct(reader, CurveMapping, &brush->automasking_cavity_curve);
  if (brush->automasking_cavity_curve) {
    BKE_curvemapping_blend_read(reader, brush->automasking_cavity_curve);
  }
  else {
    brush->automasking_cavity_curve = BKE_sculpt_default_cavity_curve();
  }
 
  /* grease pencil */
  BLO_read_struct(reader, BrushGpencilSettings, &brush->gpencil_settings);
  if (brush->gpencil_settings != nullptr) {
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_sensitivity);
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_strength);
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_jitter);
 
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_rand_pressure);
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_rand_strength);
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_rand_uv);
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_rand_hue);
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_rand_saturation);
    BLO_read_struct(reader, CurveMapping, &brush->gpencil_settings->curve_rand_value);
 
    if (brush->gpencil_settings->curve_sensitivity) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_sensitivity);
    }
 
    if (brush->gpencil_settings->curve_strength) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_strength);
    }
 
    if (brush->gpencil_settings->curve_jitter) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_jitter);
    }
 
    if (brush->gpencil_settings->curve_rand_pressure) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_rand_pressure);
    }
 
    if (brush->gpencil_settings->curve_rand_strength) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_rand_strength);
    }
 
    if (brush->gpencil_settings->curve_rand_uv) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_rand_uv);
    }
 
    if (brush->gpencil_settings->curve_rand_hue) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_rand_hue);
    }
 
    if (brush->gpencil_settings->curve_rand_saturation) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_rand_saturation);
    }
 
    if (brush->gpencil_settings->curve_rand_value) {
      BKE_curvemapping_blend_read(reader, brush->gpencil_settings->curve_rand_value);
    }
  }
 
  BLO_read_struct(reader, BrushCurvesSculptSettings, &brush->curves_sculpt_settings);
  if (brush->curves_sculpt_settings) {
    BLO_read_struct(reader, CurveMapping, &brush->curves_sculpt_settings->curve_parameter_falloff);
    if (brush->curves_sculpt_settings->curve_parameter_falloff) {
      BKE_curvemapping_blend_read(reader, brush->curves_sculpt_settings->curve_parameter_falloff);
    }
  }
 
  BLO_read_struct(reader, PreviewImage, &brush->preview);
  BKE_previewimg_blend_read(reader, brush->preview);
 
  brush->icon_imbuf = nullptr;
  brush->has_unsaved_changes = false;
}
 
static void brush_blend_read_after_liblink(BlendLibReader * /*reader*/, ID *id)
{
  Brush *brush = reinterpret_cast<Brush *>(id);
 
  /* Update brush settings depending on availability of other IDs. */
  if (brush->gpencil_settings != nullptr) {
    if (brush->gpencil_settings->flag & GP_BRUSH_MATERIAL_PINNED) {
      if (!brush->gpencil_settings->material) {
        brush->gpencil_settings->flag &= ~GP_BRUSH_MATERIAL_PINNED;
      }
    }
    else {
      brush->gpencil_settings->material = nullptr;
    }
  }
}
 
static void brush_asset_metadata_ensure(void *asset_ptr, AssetMetaData *asset_data)
{
  using namespace blender;
  using namespace blender::bke;
 
  Brush *brush = reinterpret_cast<Brush *>(asset_ptr);
  BLI_assert(GS(brush->id.name) == ID_BR);
 
  /* Most names copied from brush RNA (not all are available there though). */
  constexpr std::array mode_map{
      std::tuple{"use_paint_sculpt", OB_MODE_SCULPT, "sculpt_brush_type"},
      std::tuple{"use_paint_vertex", OB_MODE_VERTEX_PAINT, "vertex_brush_type"},
      std::tuple{"use_paint_weight", OB_MODE_WEIGHT_PAINT, "weight_brush_type"},
      std::tuple{"use_paint_image", OB_MODE_TEXTURE_PAINT, "image_brush_type"},
      /* Sculpt UVs in the image editor while in edit mode. */
      std::tuple{"use_paint_uv_sculpt", OB_MODE_EDIT, "image_brush_type"},
      std::tuple{"use_paint_grease_pencil", OB_MODE_PAINT_GREASE_PENCIL, "gpencil_brush_type"},
      /* Note: Not defined in brush RNA, own name. */
      std::tuple{
          "use_sculpt_grease_pencil", OB_MODE_SCULPT_GREASE_PENCIL, "gpencil_sculpt_brush_type"},
      std::tuple{
          "use_vertex_grease_pencil", OB_MODE_VERTEX_GREASE_PENCIL, "gpencil_vertex_brush_type"},
      std::tuple{"use_weight_gpencil", OB_MODE_WEIGHT_GREASE_PENCIL, "gpencil_weight_brush_type"},
      std::tuple{"use_paint_sculpt_curves", OB_MODE_SCULPT_CURVES, "curves_sculpt_brush_type"},
  };
 
  for (const auto &[prop_name, mode, tool_prop_name] : mode_map) {
    /* Only add booleans for supported modes. */
    if (!(brush->ob_mode & mode)) {
      continue;
    }
    auto mode_property = idprop::create_bool(prop_name, true);
    BKE_asset_metadata_idprop_ensure(asset_data, mode_property.release());
 
    if (std::optional<int> brush_tool = BKE_paint_get_brush_type_from_obmode(brush, mode)) {
      auto type_property = idprop::create(tool_prop_name, *brush_tool);
      BKE_asset_metadata_idprop_ensure(asset_data, type_property.release());
    }
    else {
      BLI_assert_unreachable();
    }
  }
}
 
static AssetTypeInfo AssetType_BR = {
    /*pre_save_fn*/ brush_asset_metadata_ensure,
    /*on_mark_asset_fn*/ brush_asset_metadata_ensure,
};
 
IDTypeInfo IDType_ID_BR = {
    /*id_code*/ ID_BR,
    /*id_filter*/ FILTER_ID_BR,
    /*dependencies_id_types*/
    (FILTER_ID_BR | FILTER_ID_IM | FILTER_ID_PC | FILTER_ID_TE | FILTER_ID_MA),
    /*main_listbase_index*/ INDEX_ID_BR,
    /*struct_size*/ sizeof(Brush),
    /*name*/ "Brush",
    /*name_plural*/ N_("brushes"),
    /*translation_context*/ BLT_I18NCONTEXT_ID_BRUSH,
    /*flags*/ IDTYPE_FLAGS_NO_ANIMDATA | IDTYPE_FLAGS_NO_MEMFILE_UNDO,
    /*asset_type_info*/ &AssetType_BR,
 
    /*init_data*/ brush_init_data,
    /*copy_data*/ brush_copy_data,
    /*free_data*/ brush_free_data,
    /*make_local*/ brush_make_local,
    /*foreach_id*/ brush_foreach_id,
    /*foreach_cache*/ nullptr,
    /*foreach_path*/ brush_foreach_path,
    /*owner_pointer_get*/ nullptr,
 
    /*blend_write*/ brush_blend_write,
    /*blend_read_data*/ brush_blend_read_data,
    /*blend_read_after_liblink*/ brush_blend_read_after_liblink,
 
    /*blend_read_undo_preserve*/ nullptr,
 
    /*lib_override_apply_post*/ nullptr,
};
 
static RNG *brush_rng;
 
void BKE_brush_system_init()
{
  brush_rng = BLI_rng_new(0);
  BLI_rng_srandom(brush_rng, 31415682);
}
 
void BKE_brush_system_exit()
{
  if (brush_rng == nullptr) {
    return;
  }
  BLI_rng_free(brush_rng);
  brush_rng = nullptr;
}
 
static void brush_defaults(Brush *brush)
{
 
  const Brush *brush_def = DNA_struct_default_get(Brush);
 
#define FROM_DEFAULT(member) \
  memcpy((void *)&brush->member, (void *)&brush_def->member, sizeof(brush->member))
#define FROM_DEFAULT_PTR(member) memcpy(brush->member, brush_def->member, sizeof(brush->member))
 
  FROM_DEFAULT(blend);
  FROM_DEFAULT(flag);
  FROM_DEFAULT(weight);
  FROM_DEFAULT(size);
  FROM_DEFAULT(alpha);
  FROM_DEFAULT(hardness);
  FROM_DEFAULT(autosmooth_factor);
  FROM_DEFAULT(topology_rake_factor);
  FROM_DEFAULT(crease_pinch_factor);
  FROM_DEFAULT(normal_radius_factor);
  FROM_DEFAULT(wet_paint_radius_factor);
  FROM_DEFAULT(area_radius_factor);
  FROM_DEFAULT(disconnected_distance_max);
  FROM_DEFAULT(sculpt_plane);
  FROM_DEFAULT(plane_offset);
  FROM_DEFAULT(clone.alpha);
  FROM_DEFAULT(normal_weight);
  FROM_DEFAULT(fill_threshold);
  FROM_DEFAULT(flag);
  FROM_DEFAULT(sampling_flag);
  FROM_DEFAULT_PTR(rgb);
  FROM_DEFAULT_PTR(secondary_rgb);
  FROM_DEFAULT(spacing);
  FROM_DEFAULT(smooth_stroke_radius);
  FROM_DEFAULT(smooth_stroke_factor);
  FROM_DEFAULT(rate);
  FROM_DEFAULT(jitter);
  FROM_DEFAULT(texture_sample_bias);
  FROM_DEFAULT(texture_overlay_alpha);
  FROM_DEFAULT(mask_overlay_alpha);
  FROM_DEFAULT(cursor_overlay_alpha);
  FROM_DEFAULT(overlay_flags);
  FROM_DEFAULT_PTR(add_col);
  FROM_DEFAULT_PTR(sub_col);
  FROM_DEFAULT(stencil_pos);
  FROM_DEFAULT(stencil_dimension);
  FROM_DEFAULT(mtex);
  FROM_DEFAULT(mask_mtex);
  FROM_DEFAULT(falloff_shape);
  FROM_DEFAULT(tip_scale_x);
  FROM_DEFAULT(tip_roundness);
 
#undef FROM_DEFAULT
#undef FROM_DEFAULT_PTR
}
 
/* Datablock add/copy/free/make_local */
 
Brush *BKE_brush_add(Main *bmain, const char *name, const eObjectMode ob_mode)
{
  Brush *brush = (Brush *)BKE_id_new(bmain, ID_BR, name);
 
  brush->ob_mode = ob_mode;
 
  if (ob_mode == OB_MODE_SCULPT_CURVES) {
    BKE_brush_init_curves_sculpt_settings(brush);
  }
  else if (ELEM(ob_mode,
                OB_MODE_PAINT_GREASE_PENCIL,
                OB_MODE_SCULPT_GREASE_PENCIL,
                OB_MODE_WEIGHT_GREASE_PENCIL,
                OB_MODE_VERTEX_GREASE_PENCIL))
  {
    BKE_brush_init_gpencil_settings(brush);
  }
 
  return brush;
}
 
void BKE_brush_init_gpencil_settings(Brush *brush)
{
  if (brush->gpencil_settings == nullptr) {
    brush->gpencil_settings = MEM_cnew<BrushGpencilSettings>("BrushGpencilSettings");
  }
 
  brush->gpencil_settings->draw_smoothlvl = 1;
  brush->gpencil_settings->flag = 0;
  brush->gpencil_settings->flag |= GP_BRUSH_USE_PRESSURE;
  brush->gpencil_settings->draw_strength = 1.0f;
  brush->gpencil_settings->draw_jitter = 0.0f;
  brush->gpencil_settings->flag |= GP_BRUSH_USE_JITTER_PRESSURE;
 
  /* curves */
  brush->gpencil_settings->curve_sensitivity = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  brush->gpencil_settings->curve_strength = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  brush->gpencil_settings->curve_jitter = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
 
  brush->gpencil_settings->curve_rand_pressure = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  brush->gpencil_settings->curve_rand_strength = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  brush->gpencil_settings->curve_rand_uv = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  brush->gpencil_settings->curve_rand_hue = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  brush->gpencil_settings->curve_rand_saturation = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  brush->gpencil_settings->curve_rand_value = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
}
 
bool BKE_brush_delete(Main *bmain, Brush *brush)
{
  if (brush->id.tag & ID_TAG_INDIRECT) {
    return false;
  }
  if (ID_REAL_USERS(brush) <= 1 && ID_EXTRA_USERS(brush) == 0 &&
      BKE_library_ID_is_indirectly_used(bmain, brush))
  {
    return false;
  }
 
  BKE_id_delete(bmain, brush);
 
  return true;
}
 
void BKE_brush_init_curves_sculpt_settings(Brush *brush)
{
  if (brush->curves_sculpt_settings == nullptr) {
    brush->curves_sculpt_settings = MEM_cnew<BrushCurvesSculptSettings>(__func__);
  }
  BrushCurvesSculptSettings *settings = brush->curves_sculpt_settings;
  settings->flag = BRUSH_CURVES_SCULPT_FLAG_INTERPOLATE_RADIUS;
  settings->add_amount = 1;
  settings->points_per_curve = 8;
  settings->minimum_length = 0.01f;
  settings->curve_length = 0.3f;
  settings->curve_radius = 0.01f;
  settings->density_add_attempts = 100;
  settings->curve_parameter_falloff = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
}
 
void BKE_brush_tag_unsaved_changes(Brush *brush)
{
  if (brush && ID_IS_LINKED(brush)) {
    brush->has_unsaved_changes = true;
  }
}
 
Brush *BKE_brush_first_search(Main *bmain, const eObjectMode ob_mode)
{
  LISTBASE_FOREACH (Brush *, brush, &bmain->brushes) {
    if (brush->ob_mode & ob_mode) {
      return brush;
    }
  }
  return nullptr;
}
 
void BKE_brush_debug_print_state(Brush *br)
{
  /* create a fake brush and set it to the defaults */
  Brush def = blender::dna::shallow_zero_initialize();
  brush_defaults(&def);
 
#define BR_TEST(field, t) \
  if (br->field != def.field) { \
    printf("br->" #field " = %" #t ";\n", br->field); \
  } \
  ((void)0)
 
#define BR_TEST_FLAG(_f) \
  if ((br->flag & _f) && !(def.flag & _f)) { \
    printf("br->flag |= " #_f ";\n"); \
  } \
  else if (!(br->flag & _f) && (def.flag & _f)) { \
    printf("br->flag &= ~" #_f ";\n"); \
  } \
  ((void)0)
 
#define BR_TEST_FLAG_OVERLAY(_f) \
  if ((br->overlay_flags & _f) && !(def.overlay_flags & _f)) { \
    printf("br->overlay_flags |= " #_f ";\n"); \
  } \
  else if (!(br->overlay_flags & _f) && (def.overlay_flags & _f)) { \
    printf("br->overlay_flags &= ~" #_f ";\n"); \
  } \
  ((void)0)
 
  /* print out any non-default brush state */
  BR_TEST(normal_weight, f);
 
  BR_TEST(blend, d);
  BR_TEST(size, d);
 
  /* br->flag */
  BR_TEST_FLAG(BRUSH_AIRBRUSH);
  BR_TEST_FLAG(BRUSH_ALPHA_PRESSURE);
  BR_TEST_FLAG(BRUSH_SIZE_PRESSURE);
  BR_TEST_FLAG(BRUSH_JITTER_PRESSURE);
  BR_TEST_FLAG(BRUSH_SPACING_PRESSURE);
  BR_TEST_FLAG(BRUSH_ANCHORED);
  BR_TEST_FLAG(BRUSH_DIR_IN);
  BR_TEST_FLAG(BRUSH_SPACE);
  BR_TEST_FLAG(BRUSH_SMOOTH_STROKE);
  BR_TEST_FLAG(BRUSH_PERSISTENT);
  BR_TEST_FLAG(BRUSH_ACCUMULATE);
  BR_TEST_FLAG(BRUSH_LOCK_ALPHA);
  BR_TEST_FLAG(BRUSH_ORIGINAL_NORMAL);
  BR_TEST_FLAG(BRUSH_OFFSET_PRESSURE);
  BR_TEST_FLAG(BRUSH_SPACE_ATTEN);
  BR_TEST_FLAG(BRUSH_ADAPTIVE_SPACE);
  BR_TEST_FLAG(BRUSH_LOCK_SIZE);
  BR_TEST_FLAG(BRUSH_EDGE_TO_EDGE);
  BR_TEST_FLAG(BRUSH_DRAG_DOT);
  BR_TEST_FLAG(BRUSH_INVERSE_SMOOTH_PRESSURE);
  BR_TEST_FLAG(BRUSH_PLANE_TRIM);
  BR_TEST_FLAG(BRUSH_FRONTFACE);
  BR_TEST_FLAG(BRUSH_CUSTOM_ICON);
 
  BR_TEST_FLAG_OVERLAY(BRUSH_OVERLAY_CURSOR);
  BR_TEST_FLAG_OVERLAY(BRUSH_OVERLAY_PRIMARY);
  BR_TEST_FLAG_OVERLAY(BRUSH_OVERLAY_SECONDARY);
  BR_TEST_FLAG_OVERLAY(BRUSH_OVERLAY_CURSOR_OVERRIDE_ON_STROKE);
  BR_TEST_FLAG_OVERLAY(BRUSH_OVERLAY_PRIMARY_OVERRIDE_ON_STROKE);
  BR_TEST_FLAG_OVERLAY(BRUSH_OVERLAY_SECONDARY_OVERRIDE_ON_STROKE);
 
  BR_TEST(jitter, f);
  BR_TEST(spacing, d);
  BR_TEST(smooth_stroke_radius, d);
  BR_TEST(smooth_stroke_factor, f);
  BR_TEST(rate, f);
 
  BR_TEST(alpha, f);
 
  BR_TEST(sculpt_plane, d);
 
  BR_TEST(plane_offset, f);
 
  BR_TEST(autosmooth_factor, f);
 
  BR_TEST(topology_rake_factor, f);
 
  BR_TEST(crease_pinch_factor, f);
 
  BR_TEST(plane_trim, f);
 
  BR_TEST(texture_sample_bias, f);
  BR_TEST(texture_overlay_alpha, d);
 
  BR_TEST(add_col[0], f);
  BR_TEST(add_col[1], f);
  BR_TEST(add_col[2], f);
  BR_TEST(add_col[3], f);
  BR_TEST(sub_col[0], f);
  BR_TEST(sub_col[1], f);
  BR_TEST(sub_col[2], f);
  BR_TEST(sub_col[3], f);
 
  printf("\n");
 
#undef BR_TEST
#undef BR_TEST_FLAG
}
 
void BKE_brush_curve_preset(Brush *b, eCurveMappingPreset preset)
{
  CurveMapping *cumap = nullptr;
  CurveMap *cuma = nullptr;
 
  if (!b->curve) {
    b->curve = BKE_curvemapping_add(1, 0, 0, 1, 1);
  }
  cumap = b->curve;
  cumap->flag &= ~CUMA_EXTEND_EXTRAPOLATE;
  cumap->preset = preset;
 
  cuma = b->curve->cm;
  BKE_curvemap_reset(cuma, &cumap->clipr, cumap->preset, CURVEMAP_SLOPE_NEGATIVE);
  BKE_curvemapping_changed(cumap, false);
  BKE_brush_tag_unsaved_changes(b);
}
 
const MTex *BKE_brush_mask_texture_get(const Brush *brush, const eObjectMode object_mode)
{
  if (object_mode == OB_MODE_SCULPT) {
    return &brush->mtex;
  }
  return &brush->mask_mtex;
}
 
const MTex *BKE_brush_color_texture_get(const Brush *brush, const eObjectMode object_mode)
{
  if (object_mode == OB_MODE_SCULPT) {
    return &brush->mask_mtex;
  }
  return &brush->mtex;
}
 
float BKE_brush_sample_tex_3d(const Scene *scene,
                              const Brush *br,
                              const MTex *mtex,
                              const float point[3],
                              float rgba[4],
                              const int thread,
                              ImagePool *pool)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
  float intensity = 1.0;
  bool hasrgb = false;
 
  if (mtex == nullptr || mtex->tex == nullptr) {
    intensity = 1;
  }
  else if (mtex->brush_map_mode == MTEX_MAP_MODE_3D) {
    /* Get strength by feeding the vertex
     * location directly into a texture */
    hasrgb = RE_texture_evaluate(mtex, point, thread, pool, false, false, &intensity, rgba);
  }
  else if (mtex->brush_map_mode == MTEX_MAP_MODE_STENCIL) {
    float rotation = -mtex->rot;
    const float point_2d[2] = {point[0], point[1]};
    float x, y;
    float co[3];
 
    x = point_2d[0] - br->stencil_pos[0];
    y = point_2d[1] - br->stencil_pos[1];
 
    if (rotation > 0.001f || rotation < -0.001f) {
      const float angle = atan2f(y, x) + rotation;
      const float flen = sqrtf(x * x + y * y);
 
      x = flen * cosf(angle);
      y = flen * sinf(angle);
    }
 
    if (fabsf(x) > br->stencil_dimension[0] || fabsf(y) > br->stencil_dimension[1]) {
      zero_v4(rgba);
      return 0.0f;
    }
    x /= (br->stencil_dimension[0]);
    y /= (br->stencil_dimension[1]);
 
    co[0] = x;
    co[1] = y;
    co[2] = 0.0f;
 
    hasrgb = RE_texture_evaluate(mtex, co, thread, pool, false, false, &intensity, rgba);
  }
  else {
    float rotation = -mtex->rot;
    const float point_2d[2] = {point[0], point[1]};
    float x = 0.0f, y = 0.0f; /* Quite warnings */
    float invradius = 1.0f;   /* Quite warnings */
    float co[3];
 
    if (mtex->brush_map_mode == MTEX_MAP_MODE_VIEW) {
      /* keep coordinates relative to mouse */
 
      rotation -= ups->brush_rotation;
 
      x = point_2d[0] - ups->tex_mouse[0];
      y = point_2d[1] - ups->tex_mouse[1];
 
      /* use pressure adjusted size for fixed mode */
      invradius = 1.0f / ups->pixel_radius;
    }
    else if (mtex->brush_map_mode == MTEX_MAP_MODE_TILED) {
      /* leave the coordinates relative to the screen */
 
      /* use unadjusted size for tiled mode */
      invradius = 1.0f / ups->start_pixel_radius;
 
      x = point_2d[0];
      y = point_2d[1];
    }
    else if (mtex->brush_map_mode == MTEX_MAP_MODE_RANDOM) {
      rotation -= ups->brush_rotation;
      /* these contain a random coordinate */
      x = point_2d[0] - ups->tex_mouse[0];
      y = point_2d[1] - ups->tex_mouse[1];
 
      invradius = 1.0f / ups->pixel_radius;
    }
 
    x *= invradius;
    y *= invradius;
 
    /* it is probably worth optimizing for those cases where
     * the texture is not rotated by skipping the calls to
     * atan2, sqrtf, sin, and cos. */
    if (rotation > 0.001f || rotation < -0.001f) {
      const float angle = atan2f(y, x) + rotation;
      const float flen = sqrtf(x * x + y * y);
 
      x = flen * cosf(angle);
      y = flen * sinf(angle);
    }
 
    co[0] = x;
    co[1] = y;
    co[2] = 0.0f;
 
    hasrgb = RE_texture_evaluate(mtex, co, thread, pool, false, false, &intensity, rgba);
  }
 
  intensity += br->texture_sample_bias;
 
  if (!hasrgb) {
    rgba[0] = intensity;
    rgba[1] = intensity;
    rgba[2] = intensity;
    rgba[3] = 1.0f;
  }
  /* For consistency, sampling always returns color in linear space */
  else if (ups->do_linear_conversion) {
    IMB_colormanagement_colorspace_to_scene_linear_v3(rgba, ups->colorspace);
  }
 
  return intensity;
}
 
float BKE_brush_sample_masktex(
    const Scene *scene, Brush *br, const float point[2], const int thread, ImagePool *pool)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
  MTex *mtex = &br->mask_mtex;
  float rgba[4], intensity;
 
  if (!mtex->tex) {
    return 1.0f;
  }
  if (mtex->brush_map_mode == MTEX_MAP_MODE_STENCIL) {
    float rotation = -mtex->rot;
    const float point_2d[2] = {point[0], point[1]};
    float x, y;
    float co[3];
 
    x = point_2d[0] - br->mask_stencil_pos[0];
    y = point_2d[1] - br->mask_stencil_pos[1];
 
    if (rotation > 0.001f || rotation < -0.001f) {
      const float angle = atan2f(y, x) + rotation;
      const float flen = sqrtf(x * x + y * y);
 
      x = flen * cosf(angle);
      y = flen * sinf(angle);
    }
 
    if (fabsf(x) > br->mask_stencil_dimension[0] || fabsf(y) > br->mask_stencil_dimension[1]) {
      zero_v4(rgba);
      return 0.0f;
    }
    x /= (br->mask_stencil_dimension[0]);
    y /= (br->mask_stencil_dimension[1]);
 
    co[0] = x;
    co[1] = y;
    co[2] = 0.0f;
 
    RE_texture_evaluate(mtex, co, thread, pool, false, false, &intensity, rgba);
  }
  else {
    float rotation = -mtex->rot;
    const float point_2d[2] = {point[0], point[1]};
    float x = 0.0f, y = 0.0f; /* Quite warnings */
    float invradius = 1.0f;   /* Quite warnings */
    float co[3];
 
    if (mtex->brush_map_mode == MTEX_MAP_MODE_VIEW) {
      /* keep coordinates relative to mouse */
 
      rotation -= ups->brush_rotation_sec;
 
      x = point_2d[0] - ups->mask_tex_mouse[0];
      y = point_2d[1] - ups->mask_tex_mouse[1];
 
      /* use pressure adjusted size for fixed mode */
      invradius = 1.0f / ups->pixel_radius;
    }
    else if (mtex->brush_map_mode == MTEX_MAP_MODE_TILED) {
      /* leave the coordinates relative to the screen */
 
      /* use unadjusted size for tiled mode */
      invradius = 1.0f / ups->start_pixel_radius;
 
      x = point_2d[0];
      y = point_2d[1];
    }
    else if (mtex->brush_map_mode == MTEX_MAP_MODE_RANDOM) {
      rotation -= ups->brush_rotation_sec;
      /* these contain a random coordinate */
      x = point_2d[0] - ups->mask_tex_mouse[0];
      y = point_2d[1] - ups->mask_tex_mouse[1];
 
      invradius = 1.0f / ups->pixel_radius;
    }
 
    x *= invradius;
    y *= invradius;
 
    /* it is probably worth optimizing for those cases where
     * the texture is not rotated by skipping the calls to
     * atan2, sqrtf, sin, and cos. */
    if (rotation > 0.001f || rotation < -0.001f) {
      const float angle = atan2f(y, x) + rotation;
      const float flen = sqrtf(x * x + y * y);
 
      x = flen * cosf(angle);
      y = flen * sinf(angle);
    }
 
    co[0] = x;
    co[1] = y;
    co[2] = 0.0f;
 
    RE_texture_evaluate(mtex, co, thread, pool, false, false, &intensity, rgba);
  }
 
  CLAMP(intensity, 0.0f, 1.0f);
 
  switch (br->mask_pressure) {
    case BRUSH_MASK_PRESSURE_CUTOFF:
      intensity = ((1.0f - intensity) < ups->size_pressure_value) ? 1.0f : 0.0f;
      break;
    case BRUSH_MASK_PRESSURE_RAMP:
      intensity = ups->size_pressure_value + intensity * (1.0f - ups->size_pressure_value);
      break;
    default:
      break;
  }
 
  return intensity;
}
 
/* Unified Size / Strength / Color */
 
/* XXX: be careful about setting size and unprojected radius
 * because they depend on one another
 * these functions do not set the other corresponding value
 * this can lead to odd behavior if size and unprojected
 * radius become inconsistent.
 * the biggest problem is that it isn't possible to change
 * unprojected radius because a view context is not
 * available.  my usual solution to this is to use the
 * ratio of change of the size to change the unprojected
 * radius.  Not completely convinced that is correct.
 * In any case, a better solution is needed to prevent
 * inconsistency. */
 
const float *BKE_brush_color_get(const Scene *scene, const Paint *paint, const Brush *brush)
{
  if (BKE_paint_use_unified_color(scene->toolsettings, paint)) {
    return scene->toolsettings->unified_paint_settings.rgb;
  }
  return brush->rgb;
}
 
const float *BKE_brush_secondary_color_get(const Scene *scene,
                                           const Paint *paint,
                                           const Brush *brush)
{
  if (BKE_paint_use_unified_color(scene->toolsettings, paint)) {
    return scene->toolsettings->unified_paint_settings.secondary_rgb;
  }
  return brush->secondary_rgb;
}
 
void BKE_brush_color_set(Scene *scene, const Paint *paint, Brush *brush, const float color[3])
{
  if (BKE_paint_use_unified_color(scene->toolsettings, paint)) {
    UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
    copy_v3_v3(ups->rgb, color);
  }
  else {
    copy_v3_v3(brush->rgb, color);
    BKE_brush_tag_unsaved_changes(brush);
  }
}
 
void BKE_brush_size_set(Scene *scene, Brush *brush, int size)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  /* make sure range is sane */
  CLAMP(size, 1, MAX_BRUSH_PIXEL_RADIUS);
 
  if (ups->flag & UNIFIED_PAINT_SIZE) {
    ups->size = size;
  }
  else {
    brush->size = size;
    BKE_brush_tag_unsaved_changes(brush);
  }
}
 
int BKE_brush_size_get(const Scene *scene, const Brush *brush)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
  int size = (ups->flag & UNIFIED_PAINT_SIZE) ? ups->size : brush->size;
 
  return size;
}
 
bool BKE_brush_use_locked_size(const Scene *scene, const Brush *brush)
{
  const short us_flag = scene->toolsettings->unified_paint_settings.flag;
 
  return (us_flag & UNIFIED_PAINT_SIZE) ? (us_flag & UNIFIED_PAINT_BRUSH_LOCK_SIZE) :
                                          (brush->flag & BRUSH_LOCK_SIZE);
}
 
bool BKE_brush_use_size_pressure(const Brush *brush)
{
  return brush->flag & BRUSH_SIZE_PRESSURE;
}
 
bool BKE_brush_use_alpha_pressure(const Brush *brush)
{
  return brush->flag & BRUSH_ALPHA_PRESSURE;
}
 
bool BKE_brush_sculpt_has_secondary_color(const Brush *brush)
{
  return ELEM(brush->sculpt_brush_type,
              SCULPT_BRUSH_TYPE_BLOB,
              SCULPT_BRUSH_TYPE_DRAW,
              SCULPT_BRUSH_TYPE_DRAW_SHARP,
              SCULPT_BRUSH_TYPE_INFLATE,
              SCULPT_BRUSH_TYPE_CLAY,
              SCULPT_BRUSH_TYPE_CLAY_STRIPS,
              SCULPT_BRUSH_TYPE_CLAY_THUMB,
              SCULPT_BRUSH_TYPE_PINCH,
              SCULPT_BRUSH_TYPE_CREASE,
              SCULPT_BRUSH_TYPE_LAYER,
              SCULPT_BRUSH_TYPE_FLATTEN,
              SCULPT_BRUSH_TYPE_FILL,
              SCULPT_BRUSH_TYPE_SCRAPE,
              SCULPT_BRUSH_TYPE_MASK);
}
 
void BKE_brush_unprojected_radius_set(Scene *scene, Brush *brush, float unprojected_radius)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  if (ups->flag & UNIFIED_PAINT_SIZE) {
    ups->unprojected_radius = unprojected_radius;
  }
  else {
    brush->unprojected_radius = unprojected_radius;
    BKE_brush_tag_unsaved_changes(brush);
  }
}
 
float BKE_brush_unprojected_radius_get(const Scene *scene, const Brush *brush)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  return (ups->flag & UNIFIED_PAINT_SIZE) ? ups->unprojected_radius : brush->unprojected_radius;
}
 
void BKE_brush_alpha_set(Scene *scene, Brush *brush, float alpha)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  if (ups->flag & UNIFIED_PAINT_ALPHA) {
    ups->alpha = alpha;
  }
  else {
    brush->alpha = alpha;
    BKE_brush_tag_unsaved_changes(brush);
  }
}
 
float BKE_brush_alpha_get(const Scene *scene, const Brush *brush)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  return (ups->flag & UNIFIED_PAINT_ALPHA) ? ups->alpha : brush->alpha;
}
 
float BKE_brush_weight_get(const Scene *scene, const Brush *brush)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  return (ups->flag & UNIFIED_PAINT_WEIGHT) ? ups->weight : brush->weight;
}
 
void BKE_brush_weight_set(const Scene *scene, Brush *brush, float value)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  if (ups->flag & UNIFIED_PAINT_WEIGHT) {
    ups->weight = value;
  }
  else {
    brush->weight = value;
    BKE_brush_tag_unsaved_changes(brush);
  }
}
 
int BKE_brush_input_samples_get(const Scene *scene, const Brush *brush)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  return (ups->flag & UNIFIED_PAINT_INPUT_SAMPLES) ? ups->input_samples : brush->input_samples;
}
 
void BKE_brush_input_samples_set(const Scene *scene, Brush *brush, int value)
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
 
  if (ups->flag & UNIFIED_PAINT_INPUT_SAMPLES) {
    ups->input_samples = value;
  }
  else {
    brush->input_samples = value;
    BKE_brush_tag_unsaved_changes(brush);
  }
}
 
void BKE_brush_scale_unprojected_radius(float *unprojected_radius,
                                        int new_brush_size,
                                        int old_brush_size)
{
  float scale = new_brush_size;
  /* avoid division by zero */
  if (old_brush_size != 0) {
    scale /= float(old_brush_size);
  }
  (*unprojected_radius) *= scale;
}
 
void BKE_brush_scale_size(int *r_brush_size,
                          float new_unprojected_radius,
                          float old_unprojected_radius)
{
  float scale = new_unprojected_radius;
  /* avoid division by zero */
  if (old_unprojected_radius != 0) {
    scale /= new_unprojected_radius;
  }
  (*r_brush_size) = int(float(*r_brush_size) * scale);
}
 
void BKE_brush_jitter_pos(const Scene &scene,
                          const Brush &brush,
                          const float pos[2],
                          float jitterpos[2])
{
  float rand_pos[2];
  float spread;
  int diameter;
 
  do {
    rand_pos[0] = BLI_rng_get_float(brush_rng) - 0.5f;
    rand_pos[1] = BLI_rng_get_float(brush_rng) - 0.5f;
  } while (len_squared_v2(rand_pos) > square_f(0.5f));
 
  if (brush.flag & BRUSH_ABSOLUTE_JITTER) {
    diameter = 2 * brush.jitter_absolute;
    spread = 1.0;
  }
  else {
    diameter = 2 * BKE_brush_size_get(&scene, &brush);
    spread = brush.jitter;
  }
  /* find random position within a circle of diameter 1 */
  jitterpos[0] = pos[0] + 2 * rand_pos[0] * diameter * spread;
  jitterpos[1] = pos[1] + 2 * rand_pos[1] * diameter * spread;
}
 
void BKE_brush_randomize_texture_coords(UnifiedPaintSettings *ups, bool mask)
{
  /* we multiply with brush radius as an optimization for the brush
   * texture sampling functions */
  if (mask) {
    ups->mask_tex_mouse[0] = BLI_rng_get_float(brush_rng) * ups->pixel_radius;
    ups->mask_tex_mouse[1] = BLI_rng_get_float(brush_rng) * ups->pixel_radius;
  }
  else {
    ups->tex_mouse[0] = BLI_rng_get_float(brush_rng) * ups->pixel_radius;
    ups->tex_mouse[1] = BLI_rng_get_float(brush_rng) * ups->pixel_radius;
  }
}
 
void BKE_brush_calc_curve_factors(const eBrushCurvePreset preset,
                                  const CurveMapping *cumap,
                                  const blender::Span<float> distances,
                                  const float brush_radius,
                                  const blender::MutableSpan<float> factors)
{
  BLI_assert(factors.size() == distances.size());
 
  const float radius_rcp = blender::math::rcp(brush_radius);
  switch (preset) {
    case BRUSH_CURVE_CUSTOM: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        factors[i] *= BKE_curvemapping_evaluateF(cumap, 0, distance * radius_rcp);
      }
      break;
    }
    case BRUSH_CURVE_SHARP: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        const float factor = 1.0f - distance * radius_rcp;
        factors[i] *= factor * factor;
      }
      break;
    }
    case BRUSH_CURVE_SMOOTH: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        const float factor = 1.0f - distance * radius_rcp;
        factors[i] *= 3.0f * factor * factor - 2.0f * factor * factor * factor;
      }
      break;
    }
    case BRUSH_CURVE_SMOOTHER: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        const float factor = 1.0f - distance * radius_rcp;
        factors[i] *= pow3f(factor) * (factor * (factor * 6.0f - 15.0f) + 10.0f);
      }
      break;
    }
    case BRUSH_CURVE_ROOT: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        const float factor = 1.0f - distance * radius_rcp;
        factors[i] *= sqrtf(factor);
      }
      break;
    }
    case BRUSH_CURVE_LIN: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        const float factor = 1.0f - distance * radius_rcp;
        factors[i] *= factor;
      }
      break;
    }
    case BRUSH_CURVE_CONSTANT: {
      break;
    }
    case BRUSH_CURVE_SPHERE: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        const float factor = 1.0f - distance * radius_rcp;
        factors[i] *= sqrtf(2 * factor - factor * factor);
      }
      break;
    }
    case BRUSH_CURVE_POW4: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        const float factor = 1.0f - distance * radius_rcp;
        factors[i] *= factor * factor * factor * factor;
      }
      break;
    }
    case BRUSH_CURVE_INVSQUARE: {
      for (const int i : distances.index_range()) {
        const float distance = distances[i];
        if (distance >= brush_radius) {
          factors[i] = 0.0f;
          continue;
        }
        const float factor = 1.0f - distance * radius_rcp;
        factors[i] *= factor * (2.0f - factor);
      }
      break;
    }
  }
}
 
float BKE_brush_curve_strength(const eBrushCurvePreset preset,
                               const CurveMapping *cumap,
                               const float distance,
                               const float brush_radius)
{
  float p = distance;
  float strength = 1.0f;
 
  if (p >= brush_radius) {
    return 0;
  }
 
  p = p / brush_radius;
  p = 1.0f - p;
 
  switch (preset) {
    case BRUSH_CURVE_CUSTOM:
      strength = BKE_curvemapping_evaluateF(cumap, 0, 1.0f - p);
      break;
    case BRUSH_CURVE_SHARP:
      strength = p * p;
      break;
    case BRUSH_CURVE_SMOOTH:
      strength = 3.0f * p * p - 2.0f * p * p * p;
      break;
    case BRUSH_CURVE_SMOOTHER:
      strength = pow3f(p) * (p * (p * 6.0f - 15.0f) + 10.0f);
      break;
    case BRUSH_CURVE_ROOT:
      strength = sqrtf(p);
      break;
    case BRUSH_CURVE_LIN:
      strength = p;
      break;
    case BRUSH_CURVE_CONSTANT:
      strength = 1.0f;
      break;
    case BRUSH_CURVE_SPHERE:
      strength = sqrtf(2 * p - p * p);
      break;
    case BRUSH_CURVE_POW4:
      strength = p * p * p * p;
      break;
    case BRUSH_CURVE_INVSQUARE:
      strength = p * (2.0f - p);
      break;
  }
 
  return strength;
}
 
float BKE_brush_curve_strength(const Brush *br, float p, const float len)
{
  return BKE_brush_curve_strength(eBrushCurvePreset(br->curve_preset), br->curve, p, len);
}
 
float BKE_brush_curve_strength_clamped(const Brush *br, float p, const float len)
{
  float strength = BKE_brush_curve_strength(br, p, len);
 
  CLAMP(strength, 0.0f, 1.0f);
 
  return strength;
}
 
/* TODO: should probably be unified with BrushPainter stuff? */
static bool brush_gen_texture(const Brush *br,
                              const int side,
                              const bool use_secondary,
                              float *rect)
{
  const MTex *mtex = (use_secondary) ? &br->mask_mtex : &br->mtex;
  if (mtex->tex == nullptr) {
    return false;
  }
 
  const float step = 2.0 / side;
  int ix, iy;
  float x, y;
 
  /* Do normalized canonical view coords for texture. */
  for (y = -1.0, iy = 0; iy < side; iy++, y += step) {
    for (x = -1.0, ix = 0; ix < side; ix++, x += step) {
      const float co[3] = {x, y, 0.0f};
 
      float intensity;
      float rgba_dummy[4];
      RE_texture_evaluate(mtex, co, 0, nullptr, false, false, &intensity, rgba_dummy);
 
      rect[iy * side + ix] = intensity;
    }
  }
 
  return true;
}
 
ImBuf *BKE_brush_gen_radial_control_imbuf(Brush *br, bool secondary, bool display_gradient)
{
  ImBuf *im = MEM_cnew<ImBuf>("radial control texture");
  int side = 512;
  int half = side / 2;
 
  BKE_curvemapping_init(br->curve);
 
  float *rect_float = (float *)MEM_callocN(sizeof(float) * side * side, "radial control rect");
  IMB_assign_float_buffer(im, rect_float, IB_DO_NOT_TAKE_OWNERSHIP);
 
  im->x = im->y = side;
 
  const bool have_texture = brush_gen_texture(br, side, secondary, im->float_buffer.data);
 
  if (display_gradient || have_texture) {
    for (int i = 0; i < side; i++) {
      for (int j = 0; j < side; j++) {
        const float magn = sqrtf(pow2f(i - half) + pow2f(j - half));
        const float strength = BKE_brush_curve_strength_clamped(br, magn, half);
        im->float_buffer.data[i * side + j] = (have_texture) ?
                                                  im->float_buffer.data[i * side + j] * strength :
                                                  strength;
      }
    }
  }
 
  return im;
}
 
bool BKE_brush_has_cube_tip(const Brush *brush, PaintMode paint_mode)
{
  switch (paint_mode) {
    case PaintMode::Sculpt: {
      if (brush->sculpt_brush_type == SCULPT_BRUSH_TYPE_MULTIPLANE_SCRAPE) {
        return true;
      }
 
      if (ELEM(brush->sculpt_brush_type, SCULPT_BRUSH_TYPE_CLAY_STRIPS, SCULPT_BRUSH_TYPE_PAINT) &&
          (brush->tip_roundness < 1.0f || brush->tip_scale_x != 1.0f))
      {
        return true;
      }
 
      break;
    }
    default: {
      break;
    }
  }
 
  return false;
}